Air-Conditioning Box Comprising a Heat Exchanger and Air-Conditioning Method

ABSTRACT

The invention relates to an air-conditioning box comprising a heat exchanger for regulating the temperature. The air-conditioning box is used especially in systems for cooling computer centers or servers. The special design of the heat exchanger allows energy costs to be reduced such that systems operating with the air-conditioning box of the invention use less energy.

This application for patent claims priority from European patentapplication EP 09 010 989.3, filed Aug. 27, 2009, and PCT internationalapplication PCT/EP2010/005068 (published as WO 2011023327), filed Aug.18, 2010 and published Mar. 3, 2011, and the contents of these priorapplications are incorporated herein in their entirety.

TECHNICAL FIELD

The present invention relates to an air-conditioning box comprising aheat exchanger for regulating temperature. The invention furthermorerelates to a method for operating such an air-conditioning box.

BACKGROUND OF THE INVENTION

Air-conditioning boxes with a heat exchanger for temperature regulationare known from the state of the art. Furthermore, systems for regulatingtemperature are known from the state of the art for variousapplications. One possible application for such systems is the airconditioning of individual rooms or of entire buildings. Systems forregulating temperature are required in particular for the airconditioning of computer centers since the operation of computersystems, for example, server systems, generates a significantdevelopment of heat. The heat produced by the server systems mustnecessarily be removed from the space in which the server systems arestanding in order not to exceed the maximally admissible operatingtemperatures for such server systems, which are reached and exceeded ina short time without the removal of the heat produced by the servers.

DE 199 04 667 teaches a system for regulating the temperature of abuilding. The system shown in it comprises an air-conditioning apparatusthat comprises a cooling agent circuit, as a result of which an indirectcooling of the building or of individual rooms is made possible by thecooling agent. Such a cooling is especially advantageous in that theadmissible range of the relative air humidity and the desiredtemperature can be maintained very well. The cooling of the system showntakes place as a function of the outdoor temperature either as indirectfree cooling in the winter, as active cooling in the summer as well asindirect free in combination with an active cooling in the transitiontime.

The previous systems have the disadvantage that the entire air flow mustbe conducted through the heat exchanger even when the heat exchanger isturned off. As a consequence, pressure losses on the air side arecreated that bring about a greater power consumption by the ventilatorsand therefore higher energy costs. Therefore, apparatuses are known inwhich the air is conducted via a bypass when the heat exchanger isturned off in order to circumvent the pressure loss; however, this hasthe disadvantage that greater dimensions are necessary for the apparatusin order to be able to realize an appropriate bypass. However,apparatuses that have the smallest possible space requirement arepreferred particularly in computer centers in order to be able to keepthe area as small as possible.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 a shows a schematic view of the air-conditioning box inaccordance with the invention with a heat exchanger in the operatingstate.

FIG. 1 b shows the air flow in the air-conditioning box of FIG. 1 a.

FIG. 1 c shows a perspective view of the air-conditioning box of FIG. 1a.

FIG. 2 a shows a schematic view of the air-conditioning box inaccordance with the invention with the heat exchanger in the restposition.

FIG. 2 b shows the air flow in the air-conditioning box of FIG. 21.

FIG. 2 c shows a perspective view of the air-conditioning box of FIG. 2a.

SUMMARY OF THE INVETNION

Therefore, the present invention addresses the problem of makingavailable an air-conditioning box with heat exchanger that causes nohigher energy costs and air-side pressure losses are avoided to a greatextent even when the heat exchanger is turned off. The inventionaddresses a further problem of making available a system for temperatureregulation as well as a method for operating a system for temperatureregulation.

The invention solves the problem with an air-conditioning box fortemperature regulation through which at least one air flow can beconducted and that contains at least one heat exchanger, characterizedin that the heat exchanger is moveably arranged in the air-conditioningbox and can move about a point of rotation between at least oneoperating position and one position of rest. Further embodiments aresubject matter of the subclaims or are described in the following.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The air-conditioning box of the invention preferably comprises a heatexchanger that can be moved between exactly one operating position andone position of rest. In the sense of the invention the operatingposition is understood to be a position of the air-conditioning box inwhich the air entering into the air-conditioning box is guided throughthe heat exchanger and the heat exchanger is in operation. In acorresponding manner the position of rest is understood to be a positionof the heat exchanger in the air-conditioning box in which the heatexchanger is arranged outside of the air flow in the air-conditioningapparatus and is not in operation. The heat exchanger can be foldedbetween the operating position and the rest position by fastening theheat exchanger at a point of rotation in the air-conditioning box; thusthere is a foldable and/or rotatable fastening of the heat exchanger inthe air-conditioning box. The movement between the different positionstakes place, for example, electrically or hydraulically, whereby evenmechanical folding mechanisms or other movement mechanisms can be used.

In the air-conditioning box in accordance with the invention the heatexchanger is preferably movable between exactly one operating positionand exactly one rest position. In the rest position the heat exchangeris preferably arranged vertically to the bottom of the air-conditioningbox and parallel to the longer side wall of the air-conditioning box;rest positions are less preferred in which the heat exchanger isarranged obliquely in the air-conditioning box, i.e., with an angle tothe bottom that is not a right angle. Here, the maximum height of theheat exchanger in the rest position preferably corresponds to the heightof the air-conditioning box. This ensures that there is an especiallygood utilization of the present area for the tempering, in particularfor the cooling. However, even other embodiments are conceivable inwhich the heat exchanger has lesser dimensions.

The heat exchanger is preferably arranged in the air-conditioning box inaccordance with the invention in the operating state along the diagonalof the air-conditioning box between two opposite corners.

The heat exchanger is designed, for example, as an evaporator or as acooler. The control and regulation of the air-conditioning box takesplace, for example, by appropriate software.

The air-conditioning box in accordance with the invention has theadvantage over traditional air-conditioning boxes that the air-sidepressure losses can be reduced in comparison to traditionalair-conditioning boxes. When the heat exchanger is not in operation itis folded out of the air flow so that this can reduce pressure lossesotherwise produced by air flowing through the turned-off heat exchanger.This can distinctly lower the energy costs for the operation. At thesame time, a retention of the advantageous, small dimensions is possiblesince it is not necessary to conduct the air over a bypass when the heatexchanger is turned off in order to avoid pressure losses.

The air-conditioning box can be operated in different operating states,for example, at temperatures of the incoming air, also called outsideair, that are above a temperature T₁. Above a higher temperature T₂ anactive cooling could take place by the heat exchanger in operatingposition while in the range above T₁ and below T₂ only a mixed operationof active and direct cooling could take place, which could again lowerthe energy costs. Below T₁ a direct free cooling is possible, i.e., theheat exchanger is turned off and is in the rest position, so that theenergy requirement can be distinctly lowered. The using of the freecooling can ensure a high energy efficiency since no energy losses, forexample, by additional heat exchangers, occur.

In a further advantageous embodiment at least one ventilator apparatuscould be provided. This ventilator apparatus could be arranged outsideof the space to be cooled, for example, outdoors, in order to improvethe removal of the warm air. Such an additional removal of heat couldtake place by the ventilator apparatus in particular at outdoortemperatures above 17° C.

The air-conditioning boxes in accordance with the invention are used,for example, in systems for regulating the temperature of computercenters and/or of server systems, during which the 3 different operatingstates already explained above are run through. At very hightemperatures the entire system is operated in the active coolingoperating mode. In this instance the heat exchanger is arranged in theoperating position, in which all air flows through the heat exchangerand is cooled in it. At somewhat lower temperatures a mixed operationconsisting of active cooling and direct cooling takes place, i.e., onlya part of the entire air flow is conducted via the heat exchanger andanother part of the air flow is mixed into the cooled air flow outsideof the air-conditioning box. This air flow must be, for example, outdoorair or return air from the entire system. In the third operating mode ofthe direct free cooling the system is cooled exclusively with outdoorair. In this operating state the heat exchanger is in the rest positionand the air flow can pass without impediment through theair-conditioning box.

Therefore, in this instance there are two operating states in which airflows through the heat exchanger in the operating state and one state inwhich the heat exchanger is folded out of the air flow and no air flowsthrough it. This can distinctly reduce the air-side pressure losses, asexplained above.

The mixing box in accordance with the invention can be used, forexample, as part of an air-conditioning apparatus or as anair-conditioning apparatus. The air-conditioning box is used here forthe cooling of computer centers, servers, computers or server systems aswell as server racks. It is also possible to combine theair-conditioning box of the invention with a mixing box that allows afurther optimization of the operating states. Such a mixing boxcomprises, for example, different flaps, namely, an outdoor air flap, areturn air flap and a mixed air flap that permits a purposeful mixing ofdifferently tempered air flows. Such a mixing box is described in theEuropean patent application 09 005 824.9, which is referred to herewith.The combination of an air-conditioning box with this mixing box for adirect, free cooling is therefore also part of this disclosure.

The invention is described in the following using an exemplaryembodiment schematically represented in the drawings.

FIG. 1 a shows an embodiment of the air-conditioning box 1 in accordancewith the invention with a heat exchanger 9 in operating position. Theair flowing in from the top of the air-conditioning box, that ischaracterized by arrows in FIG. 1, is accordingly completely transportedthrough the heat exchanger 9 to the bottom 8 of the air-conditioningbox. The heat exchanger 9 is connected at its lower end to anarticulation 2 that functions as a point of rotation. The point ofrotation can also be arranged in other, non-shown embodiments at anotherposition along the heat exchanger. At its upper end the heat exchanger 9is delimited by an upper frame 2 against which it leans. A lateral seal5 that is fastened on the front side wall (not shown) runs parallel tothe heat exchanger 9. It is ensured by the lateral seal 5, the upperframe 2 and a sealing groove 6 on the bottom that the air flow cannot beconducted past the heat exchanger on the side or above or below it. Thebottom 8 is designed to be opened so that the air can flow through in anunimpeded manner. An electrical box 7 is arranged in the upper area ofthe air-conditioning box 1 that serves to control and regulate theair-conditioning box.

FIG. 1 c shows a perspective view in which it can be recognized that theheat exchanger 9 extends over the entire width of the air-conditioningbox and connects the two opposite corners to one another in anapproximately diagonal manner. The heat exchanger 9 rests on the sealinggroove 6 in the lower area.

FIG. 2 a shows the air-conditioning box with heat exchanger 9 in theposition of rest. The heat exchanger 9 is arranged here parallel to theside wall 4 and stands on the rail 3 located in the bottom of theair-conditioning box. Accordingly, the air flows, as can be seen in FIG.2 b, from the top of the air-conditioning box to the bottom 8 of theair-conditioning box without flowing through the heat exchanger. Theheat exchanger 9 extends here almost from the bottom 8 to the top of theair-conditioning box 1.

It can be recognized in FIG. 2 c that the lateral seal 5 is arrangedonly on the two short side walls and does not extend over the entirewidth, as well as the heat exchanger 9.

LIST OF REFERENCE NUMERALS

1 air-conditioning box

2 upper frame

3 rail

4 side wall

5 lateral seal

6 sealing grove

7 electrical box

8 bottom

9 heat exchanger

10 point of rotation

1. An air-conditioning box for temperature regulation through which atleast one air flow can be conducted and that comprises at least one heatexchanger, characterized in that the heat exchanger is movably arrangedin the air-conditioning box and can be moved about a point of rotationbetween at least one operating position and one position of rest.
 2. Theair-conditioning box according to claim 1, characterized in that theheat exchanger is arranged in the operating position in such a manner inthe air-conditioning box that the entire air flow conducted through theair-conditioning box is conducted through the heat exchanger.
 3. Theair-conditioning box according to claim 1, characterized in that theheat exchanger is arranged in the rest position in such a manner in theair-conditioning box that the air flow is completely conducted past theheat exchanger.
 4. The air-conditioning box according to claim 1,characterized in that the heat exchanger is arranged in the restposition vertically to the bottom and parallel to the side wall of theair-conditioning box.
 5. The air-conditioning box according to claim 4,characterized in that the maximum height of the heat exchangercorresponds to the height of the air-conditioning box.
 6. Theair-conditioning box according to claim 1, characterized in that theheat exchanger is arranged in the operating state along a diagonal linebetween two opposite corners of the air-conditioning box.
 7. Theair-conditioning box according to claim 1, characterized in that theheat exchanger is an evaporator or a cooler.
 8. A method for operating asystem for temperature regulation with an air-conditioning box throughwhich at least one air flow can be conducted and that comprises at leastone heat exchanger, which air-conditioning box is characterized in thatthe heat exchanger is movably arranged in the air-conditioning box andcan be moved about a point of rotation between at least one operatingposition and one position of rest, which method is characterized in thatthe air flow a. is conducted in the first operating state of the activecooling through the air-conditioning box with the heat exchanger in theoperating position, b. is conducted in the second operating state of themixed operation of the air flow through the air-conditioning box withthe heat exchanger in the operating position, and c. is conducted in athird operating state of the air flow through the air-conditioning boxwith the heat exchanger in the rest position.